The Earth-like planets
Habitable alien planets similar to Earth may not be that rare in the universe, a new study suggests.
About one in five sunlike stars observed by NASA’s planet-huntingKepler spacecraft has an Earth-size planet in the so-called habitable zone, where liquid water — and, potentially life — could exist, according to the new study. If these results apply elsewhere in the galaxy, the nearest such planet could be just 12 light-years away.
